This study, funded by the National Institute on Alcohol Abuse and Alcoholism, examines psychosocial mediators to explain discrepancies in past-30-day drinking between African American and White college student drinkers in the United States. Between 2008 and 2010, 5,845 college drinkers completed an online survey about their alcohol use. Using latent variable structural equations modeling, we investigated the relationships between ethnicity, drinking beliefs, and students' past 30-day alcohol use. Drinking beliefs-i.e., positive expectancies, perceived norms, and disapproval of alcohol use-fully mediated the relationship between ethnicity and drinking behaviors. Study limitations and directions for future research are discussed.